Recently both me and Jon went to a gun show, it was great there were dealers and just people like us who would bring their guns with them to sell.
First thing I did was a quick scan over all the weapons that were in the building, I didn't want to miss out on a good deal on certain firearms I wanted to purchase. Then after my scan I went back to the beginning and went through each booth and talked to the people behind the tables. The people there were very helpful, any questions asked by me or Jon got straight from the hip answers all from personal experiance.
There was no sales tax involved on the used guns, a huge advantage in buying a high doller firearm. There were people there who had brought along their rare collectable rifles, one guy had an anti tank rifle there, it was a L-39 Lahti 20 mm Anti-Tank Cannon. It's massive magazine only carried 10 rds but beleive it or not this rifle could make tanks look like a tin can in a gravel pit at the end of a long shooting day, yeah that forced the germans to make better tanks, it was designed in 1939 and manufactured in finland during WW II. A few other guys brought their Uzi's and some other fully auto weapon systems and even a bazooka. The great thing about all this is anyone who goes can handle anything on the tables!
I ended up buying two firearms there and went away wishing I could have bought more.